Volcanic ash

Volcanic Ash is a members-only item on the OSRS Grand Exchange in the other category.

In-game examine text: "One of the ingredients for making ultra compost."

It has a Grand Exchange buy limit of 13,000 every four hours, a high alchemy value of 120 gp, and item ID 21622.

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Volcanic Ash shows an active flip setup with a margin of +2 gp and 1,403,015 trades over the last 24 hours.

At the buy limit of 13,000 every four hours, max profit per cycle is about 26.0k gp — high margin with healthy liquidity.